Hello Channabasappa,
The most recent version of TI-RTOS uses a kernel version of 6.37.00.20. According to the supported devices list, MSP430F5338 is supported.
http://software-dl.ti.com/dsps/dsps_public_sw/sdo_sb/targetcontent/tirtos/1_20_00_28/exports/docs/products/bios_6_37_00_20/docs/cdoc/ti/sysbios/family/doc-files/devices.html
Using TI-RTOS, or any RTOS, should not impose a limitation with respect to the BSL. The BSL is in a separate section of flash and, unless modified or erased, would work the same regardless of the presence of an RTOS.
